1. Field of the Invention
In general, the invention relates to swimming pool covers.
2. Description of Related Art
According to industry sources, there were 8.6 million residential swimming pools and 309,000 public swimming pools in the United States in 2013. In many areas, swimming pools are an indelible feature of the suburban landscape and a quintessential part of suburban recreation, in addition to their prominent role in exercise and athletic competition.
Most residential swimming pools are outdoors and are either in-ground or above ground. Particularly in warm climates, where an outdoor swimming pool can be used year round, the pool may be surrounded by a screened enclosure, which prevents leaves and other detritus from falling into the pool. However, screened enclosures can present considerable cost and maintenance issues, and are far from universal.
Where a screened enclosure is not available, or where the local climate is too cold for year-round swimming, swimming pools are often covered when they are not in use. Various types of swimming pool covers are available. At its most basic, a swimming pool cover may be little more than a sheet of plastic, typically vinyl. More complex versions may have insulation. Of course, not all swimming pool covers are in sheet form—U.S. Pat. No. 4,270,232 to Ballew, for example, discloses a cover made of discrete segments that float next to one another on the surface of the water. At least portions of those segments are transparent and transmit heat.
Most outdoor swimming pools are not automatically heated or cooled; the temperature of the water is thus dependent on the environment and the weather. However, the temperature of a swimming pool's water is a major factor in having a comfortable and productive swimming experience. While a basic swimming pool cover allows some amount of solar energy to be absorbed by the swimming pool water, the basic swimming pool cover only allows the pool water to absorb a fraction of the available energy. In fact, most basic swimming pool covers actually provide shade over a swimming pool, much like an umbrella, and actually reduce the amount of solar energy absorbed by the swimming pool water.